Envelope feeder

ABSTRACT

An envelope feeder for feeding a single envelope at a time from the bottom of a stack of envelopes to a filling station of an envelope stuffing machine includes a substantially V-shaped hopper for holding a stack of envelopes in a substantially vertical position. A feed roller is provided at the bottom of the stack and is in contact feeding engagement with the face of the lower-most envelope in the stack. Positioned immediately in front of the envelope to be fed from the hopper there is provided a separator means comprising an upper retard member and a lower transport roller in engagement with the retard member for separating and advancing the envelope fed from the hopper by the feed roller. Adjusting means is also provided for positioning the retard member with respect to the transport roller such that the nip therebetween can be varied to accommodate the particular thickness of the envelopes being fed.

United States Patent [191 Dorer Se t. 2 1975 ENVELOPE FEEDER [75] Inventor: Wilfried Dorer, Donaueschingen, 'm schacher Germany ASSlSIaIll Examiner-Bruce H. Stoner, Jr.

Attorney, Agent, or Firm-Sol L. Goldstein [73] Assignee: Mathias Bauerle GmbH, St.

Georgen, Germany [57] ABSTRACT [22] Filed: Mar. 25, 1974 An envelope feeder for feeding a single envelope at a time from the bottom of a stack of envelopes to a fill- [211 Appl' 454,251 ing station of an envelope stuffing machine includes a substantially V-shaped hopper for holding a stack of 30 Foreign Appucation p Data envelopes in a substantially vertical position. A feed May 3 1973 Germany 2322278 roller is provided at the bottom of the stack and is in contact feeding engagement with the face of the low- 52 us. (:1. 271 125- 271 166; 271 167 mmedately Int Cl 2 l B65" Q in front of the envelope to be fed from the hopper [58] Fie'ld 165 166 there is provided a separator means comprising an 13 131 35 6 upper retard member and a lower transport roller in engagement with the retard member for separating d advancing the envelope fed from the hopper by [56] References Cited an the feed roller. Ad ustmg means is also provided for UNITED STATES PATENTS positioning the retard member with respect to the Bush transport roller uch the nip therebetween can be 2 varied to accommodate the particular thickness of the c nei er. 3,424,453 1/1969 Halbert 271 166 x envekpes bemg 11/1973 Mclnemy 271/125 8 Claims, 1 Drawing Figure ENVELOPE FEEDER BACKGROUND OF THE INVENTION It is customary practice in the art of envelope stuffing machines to feed the envelopes to the filling station, whereat the material delivered generally bya folding device is introduced into the envelope, with the flap of the envelope lying on top or facing upwardly. In known envelope feeding devices of this kind, the envelopes are fed either individually from the top of the stack of envelopes or are fed singly from the bottom of the stack. However, in either case only a limited number of envelopes can be placed in the hopper holding the stack of envelopes since in order to feed the envelopes from the top of the stack it is necessary that the envelopes be placed in a fanned or overlapping relationship, thereby requiring an excessively long hopper if more than just a limited number of envelopes were to be accommodated therein. Devices for feeding envelopes from the top of the stack are usually provided with a slightly inclined feed table for holding the envelopes and, therefore, result in a fairly wide and bulky device as shown, for example, in German Pat. No. l,76l,792. In the case of feeding envelopes from the bottom of the stack, only a limited number of envelopes can be placed in the hopper because the excessive weight of a large stack of envelopes creates substantial friction on the lowermost envelopes in the stack thereby causing problems in proper separation and feeding of the lower-most envelope from the stack.

To maintain the size .and space requirements for an envelope feeder at a minimum, a preferred envelope feeder is one in which the envelopes are stacked in substantially vertical array and the envelopes are singly fed from the bottom of the stack. Devices for feeding envelopes from the bottom of the stack normally also resort to a slightly inclined feed table on which the envelopes to be fed are arranged in a vertical fashion such that the envelopes stand on edge. To provide a means for urging the lower-most envelope in the stack against the feed member for separating and feeding'the envelope. it is necessary to provide a weight member acting or pressing against the rear of the stack. One such arrangement is shown in German Pat. No. 902,619.

SUMMARY OF THE INVENTION The present invention provides a bottom of the stack envelope feeder which can accommodate a considerably larger supply of envelopes in the feed hopper, as compared to the prior art devices, without any adverse affects to the envelope separating and feeding functions as a result of the added weight of the stack of the envelopes.

It is an object of the present invention to provide an envelope feed hopper having an inclined front wall provided with a friction surface for supporting the lead edges ofthe envelopes, and a rear wall inclined in a direction opposite to the inclination of the front wall for supporting the trailing edges of the envelopes. The inclined front wall is provided as its lower end with a curved surface coacting with a retard member positioned adjacent the lead edge of the envelope to be fed from the bottom of the stack. As the envelopes are lowered by gravity towards a feeding position their lead edges move out of engagement with the inclined front wall and are supported and gradually guided by the curved surface at the lower end of the front wall and an extension thereof provided by the retard member 10, and their trailing edges are supported on a lower section of the inclined'rear wall. Because only a few envelopes at a time assume this posture approaching the feeding position, and the weight of the bulk of the envelopes in the hopper is supported by the non-curved, friction surface portion of the inclined front wall and an upper section of the inclined rear -wall, there is only minimum weight on the lower-most envelope in the stack which permits proper separation and feeding of the envelope from the hopper.

Another object of the inventi on'is to provide an envelope feed device of compact. construction, but one which provides a hopper for accommodating considerably more envelopes than the prior art devices without increasing the weight of the stack of envelopes on the lower-most envelope, such as to create excessive frictional resistance on the envelope to be fed and hamper the proper separation and feeding of the envelope from the bottom of the stack.

Another object of the invention is to provide a driven feed roller in engagement with the face of the bottom envelope to be fed from the stack. The axis of the feed roller lies in a plane corresponding approximately to a plane defined by an extension of the inclined front wall so as to position the feed roller near the lead edge of the envelope being fed to further assure positive gripping and advancement of the envelope from the stack.

A further object of the invention is to provide resilient means associated with the retard and transport members to permit separation thereof to accommodate envelopes of varying thicknesses.

Other objects, features and advantages will appear hereinafter as the description proceeds.

IN, THE DRAWING The-drawing illustrates a side elevation, in cross section, of an envelope feeder for feeding and separating envelopes from the bottom of a stack of envelopes in accordance with the present, invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT With reference to the drawing there is shown an envelope feed device including an inclined front wall I for supporting the lead edges of a stack of envelopes 4. The front wall 1 is inclined at an angle a of about from a horizontal plane in the direction of envelope feed. A rear wall 3 is provided for supporting and guiding the trailing edges of the stack of envelopes 4 as they are lowered in the direction of arrow 2'and approach the feeding position and includes a support plate 5 inclined in a direction opposite to the inclination of the front wall 1. The support plate 5 terminates in a horizontal base 6 adjustably secured by fastening means 7 to a stand 8. This arrangement provides for horizontal movement of the support plate 5 to accommodate the stacking and feeding of envelopes of different sizes. The support plate 5 is inclined at an angle [3 about equal to the angle a ofinclination of the front wall I except that the support plate 5 is inclined in the opposite direction from the front wall 1 such that the front wall 1 and the rear wall 3 form therebetween a generally V- shaped hopper providing an open, narrow exitway at the bottom thereof.

The inside face of the front wall 1 which supports the lead edges of the envelopes is provided with a friction coating 9 of rubber or similar material which extends over approximately the entire inside surface of the front wall 1. The arrangement of the front wall. 1 and the friction coating 9- thereon is such that they lie in a plane that is approximately tangent to the circumference of a retard member 10.

The retard member 10 is supported on a pivotable lever 11 at a position immediately adjacent the lead edge of the lower-most envelope in the stack. The lever 11 is supported for pivotable movement about an axis of an upper drive roller 12 of a pair of drive rollers 12 and 13, and the lever 11 is urged by a spring 14 in a counter-clockwise direction as viewed in the drawing against an adjustable stop 15. The adjustable stop 15 permits setting the nip of the retard member 10 and the transport roller 16 at a'proper gap setting to accommodate the thickness of the envelope being fed so that only a single envelope at a time will be gripped and advanced by the retard member 10 and the transport roller 16. The retard member 10 and 16 function as a separator means in that the retard member 10 is effective to arrest and prevent forward movement of the envelope lying on top of the lower-most envelope being fed from the stack 4. A feed roller 17 is rotatably mounted at the exitway under the stack of envelopes 4 for drivingly engaging the face of the ower-most envelope and separating the envelope from the stack and advancing it along a feed path from the exitway to the nip of the retard member 10 and the roller 16. In addition to advancing the lower-most envelope from the stack, the feed roller also supports the stack of envelopes 4. The feed roller 17 is positioned near the lead edge of the envelopes and the axis of the roller 17 lies in a plane corresponding approximately to the plane of inclination defined by an extension of the front wall 1.

The arrangement of theenvelope hopper is such that at no time do the trailing edges of more than about 20-30 envelopes of the stack 4 rest against the rear wall 3 of the support plate 5, and the lead edges of these envelopes are supported and guided by a lower, formed or curved surface of the front wall 1 which extends downwardly in the direction of the feed path towards the nip of the retard and transport members 10 and 16, respectively, and is curved to conform generally with a portion of the retard member 10, which also guides the lead edges of the envelopes by providing an extension from the curved surface of the front wall 1 to the nip on the feed path. In this way, only a portion of the weight of the stack 4 (20-30 envelopes) is supported and guided by a lower section of the rear wall 3 of the support plate-5 and the curved surface of the front wall 1. Because the bulk of the weight of the other envelopes in the stack is supported by the increased friction between the friction coating 9 on the front wall 1 and the lead edges of the stack of envelopes 4, only a slight pressure force of the weight of afew envelopes entering the exitway acts on the circumference of the feed roller 17 to thereby provide positive and reliable transport of the lower-most envelope from the stack. T hus,-the frictional resistance between the lower-most envelope and the penultimate envelope in the stack is maintained at a minimum such that the penultimate envelope during each feeding cycle is retained against forward movement by the retard member 10 during the separation and feeding of the lower-most envelope from the stack 4 to the nip of the retard and transport members 10 and i6 respectively.

As shown in the drawing; the rear wall 3 extends below the feed path so as to provide with the front wall 1 an exitway sufficiently large to permit passage of the envelopes 4 therethrough, as the envelopes move downwardly by gravity, while affording constant and continuous forward guidance to the envelopes at the bottom of the stack.

The resilient mounting arrangement of the retard roller l0 and the transport roller 16, provided by the spring 14 which permits separation of the retard member and the roller for accommodating thicker and thinner portions of the envelope, adds greatly to the positive and reliable operation of the device. Thus, because the envelope in the zone of the tip of the flap has at least three or four sheet thicknesses, as compared to only two sheet thicknesses in the zones of the envelope other than at the tip of the flap, the resilient arrangement permits the retard member 10 to be moved towards and away from the transport roller 16 to thereby accommodate the varying thicknesses of the envelope. Although the present invention illustrates and describes a resilient mounting arrangement associated with the retard member l0,'if desired, the same results and advantages could be achieved by resiliently supporting the transport roller 16 instead of the retard member 10.

From the foregoing, it will be appreciated that the present invention provides a novel feeding device for separating and feeding a single envelope at a time from the bottom of a stack of envelopes. The arrangement of the inclined, frictionally coated front wall for supporting the lead edges of the envelopes in the stack and the inclination of the rear wall for supporting the trailing edges of the envelopes in the stack, is such that the bulk of the weight of the envelopes in the stack is supported by these wall members and the only frictional resistance between the lower-most envelope to be fed and the feed roller is the weight of only a few envelopes at the bottom of the stack of envelopes. Although the device is compact, simple in construction and inexpensive to manufacture, it provides a large capacity hopper for accommodating a substantial number of envelopes without the weight of the stack creating undue frictional resistance to the lower-most envelope in the stack so as to hamper proper separation and feeding of the envelope from the bottom of the stack.

What is claimed is:

l. Anenvelope feeding device for feeding envelopes from the bottom of a stack of envelopes to a filling station of an envelope stuffing machine, comprising:

drive means for establishing a feed means for advancing envelopes along a feed path;

a hopper for receiving and supporting a stack of envelopes including a front wall inclined in the direction of the feed path and having a continuous uninterrupted surface for supporting the lead edges of all of the envelopes in the stack, said front wall having a surface at its lower end curved in the direction of the feed path, and a rear wall spaced from the front wall having a continuous uninterrupted surface inclined in a direction opposite to the inclination of the front wall and extending below the feed path for guiding and supporting the trailing edges of the envelopes at the bottom of the stack;

a feed member positioned to be in contact feeding engagement with the face of the lowermost envelope in the stack for advancing the envelope along the feed path from the stack, said feed member and the rear wall providing a support for the stack of envelopes;

said drive means including separator means comprising a retard member and a driven transport member forming a nip therebetween on the feed path for gripping and transporting the lowermost envelope advanced from the stack by the feed member, said retard member providing an extension of the front wall from the curved surface thereof to the nip on the feed path for guiding the lead edges of the envelopes as the envelopes approach a feeding position at the bottom of the stack;

yieldable means associated with the separator means for providing controlled separation between the re tard and the transport members for passage of the envelope therethrough; and

means for adjusting the nip to provide a selectively settable gap for accommodating envelopes of various thicknesses.

2. A device as set forth in claim 1 in which the inclination of the front wall forms an angle of about 60 70 from a horizontal plane in a direction of envelope transport.

3. A device as set forth in claim 1 in which the front wall is provided with a friction coating providing a friction angle of about 30 from a vertical plane in a direction of envelope feed for supporting the lead edges of the envelopes in the stack.

4. A device as set forth in claim 3 in which the friction coating comprises rubber.

5. A device as set forth in claim 1 in which the feed member is positioned so that its axis lies in a plane substantially in line with a plane defined by an extension of the inclined front wall.

6. A device as set forth in claim 1 in which the rear wall provides an angle of inclination corresponding substantially to the angle of inclination of the front wall but in the opposite direction.

7. A device as set forth in claim 1 which further includes adjustment means associated with the rear wall for selectively positioning the rear wall with respect to the front wall for accommodating envelopes of different sizes.

8. An envelope feeding device for feeding envelopes from the bottom of a stack of envelopes to a filling station of an envelope stuffing machine, comprising:

drive means for establishing a feed means for advanc ing envelopes along a feed path;

a generally V-shaped hopper having at least front and rear wall portions converging toward one another to form an open, narrow exitway at the bottom thereof, said front wall having a surface at its lower end curved in the direction of the feed path and said rear wall extending below the feed path, said hopper being adapted to receive a stack of envelopes wherein one edge of each of the envelopes is supported by a continuous uninterrupted surface of the front wall, and the rear wall is provided with a continuous uninterrupted surface which supports the stack and guides the envelopes entering said exitway;

a feed member positioned at the exitway for drivingly engaging the lowermost envelope in the stack and advancing the envelope along the feed path from the exitway, said feed member and the rear wall providing a support for the stack of envelopes; and

said drive means including separator means positioned on the feed path adjacent the front wall comprising a retard member and a driven transport member forming a nip therebetween on the feed path for gripping and transporting the lowermost envelope while retarding movement of the envelopes immediately on top of the lowermost envelope, said retard member providing an extension of the front wall from the curved surface thereof to the nip on the feed pathfor guiding said one edge of the envelopes entering said exitway. 

1. An envelope feeding device for feeding envelopes from the bottom of a stack of envelopes to a filling station of an envelope stuffing machine, comprising: drive means for establishing a feed means for advancing envelopes along a feed path; a hopper for receiving and supporting a stack of envelopes including a front wall inclined in the direction of the feed path and having a continuous uninterrupted surface for supporting the lead edges of all of the envelopes in the stack, said front wall having a surface at its lower end curved in the direction of the feed path, and a rear wall spaced from the front wall having a continuous uninterrupted surface inclined in a direction opposite to the inclination of the front wall and extending below the feed path for guiding and supporting the trailing edges of the envelopes at the bottom of the stack; a feed member positioned to be in contact feeding engagement with the face of the lowermost envelope in the stack for advancing the envelope along the feed path from the stack, said feed member and the rear wall providing a support for the stack of envelopes; said drive means including separator means comprising a retard member and a driven transport member forming a nip therebetween on the feed path for gripping and transporting the lowermost envelope advanced from the stack by the feed member, said retard member providing an extension of the front wall from the curved surface thereoF to the nip on the feed path for guiding the lead edges of the envelopes as the envelopes approach a feeding position at the bottom of the stack; yieldable means associated with the separator means for providing controlled separation between the retard and the transport members for passage of the envelope therethrough; and means for adjusting the nip to provide a selectively settable gap for accommodating envelopes of various thicknesses.
 2. A device as set forth in claim 1 in which the inclination of the front wall forms an angle of about 60* - 70* from a horizontal plane in a direction of envelope transport.
 3. A device as set forth in claim 1 in which the front wall is provided with a friction coating providing a friction angle of about 30* from a vertical plane in a direction of envelope feed for supporting the lead edges of the envelopes in the stack.
 4. A device as set forth in claim 3 in which the friction coating comprises rubber.
 5. A device as set forth in claim 1 in which the feed member is positioned so that its axis lies in a plane substantially in line with a plane defined by an extension of the inclined front wall.
 6. A device as set forth in claim 1 in which the rear wall provides an angle of inclination corresponding substantially to the angle of inclination of the front wall but in the opposite direction.
 7. A device as set forth in claim 1 which further includes adjustment means associated with the rear wall for selectively positioning the rear wall with respect to the front wall for accommodating envelopes of different sizes.
 8. An envelope feeding device for feeding envelopes from the bottom of a stack of envelopes to a filling station of an envelope stuffing machine, comprising: drive means for establishing a feed means for advancing envelopes along a feed path; a generally V-shaped hopper having at least front and rear wall portions converging toward one another to form an open, narrow exitway at the bottom thereof, said front wall having a surface at its lower end curved in the direction of the feed path and said rear wall extending below the feed path, said hopper being adapted to receive a stack of envelopes wherein one edge of each of the envelopes is supported by a continuous uninterrupted surface of the front wall, and the rear wall is provided with a continuous uninterrupted surface which supports the stack and guides the envelopes entering said exitway; a feed member positioned at the exitway for drivingly engaging the lowermost envelope in the stack and advancing the envelope along the feed path from the exitway, said feed member and the rear wall providing a support for the stack of envelopes; and said drive means including separator means positioned on the feed path adjacent the front wall comprising a retard member and a driven transport member forming a nip therebetween on the feed path for gripping and transporting the lowermost envelope while retarding movement of the envelopes immediately on top of the lowermost envelope, said retard member providing an extension of the front wall from the curved surface thereof to the nip on the feed path for guiding said one edge of the envelopes entering said exitway. 